The University of Queensland, The Queensland Brain Institute, Brisbane, Australia.
The University of Queensland, The Queensland Brain Institute, Brisbane, Australia.
Semin Cell Dev Biol. 2021 Oct;118:50-59. doi: 10.1016/j.semcdb.2021.04.009. Epub 2021 May 3.
The anterior commissure is the most ancient of the forebrain interhemispheric connections among all vertebrates. Indeed, it is the predominant pallial commissure in all non-eutherian vertebrates, universally subserving basic functions related to olfaction and survival. A key feature of the anterior commissure is its ability to convey connections from diverse brain areas, such as most of the neocortex in non-eutherian mammals, thereby mediating the bilateral integration of diverse functions. Shared developmental mechanisms between the anterior commissure and more evolutionarily recent commissures, such as the corpus callosum in eutherians, have led to the hypothesis that the former may have been a precursor for additional expansion of commissural circuits. However, differences between the formation of the anterior commissure and other telencephalic commissures suggest that independent developmental mechanisms underlie the emergence of these connections in extant species. Here, we review the developmental mechanisms and connectivity of the anterior commissure across evolutionarily distant species, and highlight its potential functional importance in humans, both in the course of normal neurodevelopment, and as a site of plastic axonal rerouting in the absence or damage of other connections.
前连合是所有脊椎动物大脑前半球连接中最古老的。事实上，它是所有非胎盘类脊椎动物中主要的大脑皮层连合，普遍参与与嗅觉和生存相关的基本功能。前连合的一个关键特征是它能够传递来自不同脑区的连接，如大多数非胎盘类哺乳动物的新皮质，从而介导不同功能的双侧整合。前连合和更进化后期的连合（如胎盘类哺乳动物的胼胝体）之间共享的发育机制，导致了这样的假设，即前者可能是其他连合回路进一步扩展的前体。然而，前连合和其他端脑连合的形成之间的差异表明，这些连接在现存物种中的出现是由独立的发育机制所决定的。在这里，我们回顾了跨越进化距离的物种中前连合的发育机制和连接性，并强调了它在人类中的潜在功能重要性，包括在正常神经发育过程中，以及在其他连接缺失或损伤时作为轴突再路由的部位。
